Mass Air Flow Sensor Working Principle and Replacement Cost

The mass air flow sensor keeps track of how much air flows into the internal combustion engine. Once it has a volume measurement of the air, it transmits this information to the engine control unit or central computer of the vehicle. Every new vehicle has numerous sensors which send information to the engine control unit. However, the mass air flow sensor is one of the most important ones for the engine because it can affect virtually all the functions and operations of the engine. If you ever end up with a bad mass air flow sensor, then you can expect your vehicle to become undrivable very quickly.

Working Principle

The engine has an intake tube where the outside air enters through. But before the air can reach the engine, it must go through an air filter first. That way, all the impurities in the air will not get inside the engine and cause problems there. Once the air volume successfully makes it through the air filter and then builds inside the engine, the mass air flow sensor measures the amount of air volume. It then sends a report of the data to the engine control unit. Based on the amount of air that is building in the engine, the control unit will know how much fuel to place in the internal combustion chamber. This ensures that an even mixture of fuel and air is in there.

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Common Symptoms of Problems

There is a wide variety of symptoms that will occur if your mass air flow sensor ever goes bad. The first noticeable symptom will probably be the Check Engine light coming on. If there are any diagnostic trouble codes that come up on your car’s computer, look up these codes in your owner’s manual to see what they refer to. More than likely, the codes will refer to a problem with the air flow. This should be a clear indicator that your mass air flow sensor is not working.

If the engine control unit receives incorrection information about the volume of air in the engine, it may tell the fuel injectors to allow more fuel to flow into the engine than is necessary. If there is too much fuel in the combustion chamber, then it will cause a lot more burning to take place. This will result in black smoke coming out of the exhaust. If this kind of activity continues, you will experience symptoms which will limit the performance of the engine. These symptoms include acceleration hesitation, engine idling, misfires, poor fuel economy, and loss of power.

At this point, driving your vehicle will be totally dangerous. You can’t have an engine with such an unpredictable performance like this. You would be risking the lives of yourself, your passengers, and everyone else that is on the road. Therefore, your best move would be to take your vehicle to a qualified mechanic and have them replace the mass air flow sensor before it makes things worse for your engine.

Replacement Cost

The mass air flow sensor is not the most expensive part in the world. In fact, it is cheap enough to replace without needing to do it yourself. Since it doesn’t take that much time for a professional mechanic to do the replacement job, you can expect there to be lower labor costs for this.

The replacement cost of a mass air flow sensor can be anywhere from $220 to $470. The parts cost should be between $190 and $400 while the labor costs will be anywhere from $30 to $70. There are also added fees and taxes included on top of these costs. Therefore, you can expect to pay $250 to $550 at the most. The true cost will depend on the make and model of your vehicle

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